Foldable rack

ABSTRACT

A foldable rack includes a lower rack frame having front and rear frame-halves each including left and right upright rods and a plurality of vertically spaced-apart horizontal plates, and left and right guide rods disposed between the left and right upright rods of the front and rear frame-halves. The horizontal plates of the front and rear frame-halves are respectively aligned with each other. Each horizontal plate of the front and rear frame-halves is disposed between and connected pivotally to the left and right upright rods and the left and right guide rods. An upper rack frame is disposed above the lower rack frame, and includes left and right guide rod extensions that are respectively connected to and that extend upwardly from the left and right guide rods.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent application Ser. No. 12/763,673, filed by the applicant on Apr. 20, 2010, the entire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a rack, more particularly to a foldable rack.

2. Description of the Related Art

Referring to FIG. 1, a foldable rack, as disclosed in Taiwanese Publication No. M302941, includes two spaced-apart U-shaped main rods 1, a link unit 2, two locking units 3, and two horizontal plate units 4. The link unit 2 includes a U-shaped connecting rod 201 disposed between the main rods 1, two slide pieces 202 sleeved respectively and slidably on two opposite arms of the U-shaped connecting rod 201, and two pairs of link rods 203. Each link rod 203 is connected pivotally between one of the slide pieces 202 and one of the arms of a corresponding main rod 1. The locking units 3 are fixed respectively to top ends of the arms of the U-shaped connecting rod 201. When the main rods 1 are spaced apart from each other at a maximum distance, that is, when the main rods 1 are in an unfolded state, the locking units 3 are engaged to the respective slide pieces 202. When the locking units 3 are operated so as to disengage from the respective slide pieces 202, the slide pieces 202 are respectively slidable along the arms of the U-shaped connecting rod 201 to thereby move the main rods 1 close to each other to a folded state.

Although the aforesaid foldable rack can achieve its intended purpose, because the locking units 3 are fixed respectively to the top ends of the arms of the U-shaped connecting rod 201, it is difficult to add more horizontal plate units 4 to the aforesaid conventional foldable rack so as to increase the height and storage space thereof. Hence, use of the aforesaid conventional foldable rack is limited.

As to conventional computer tables, since they have a fixed structure and cannot be folded, they occupy a substantial space even in an unused state.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide a foldable rack that is capable of overcoming the aforementioned drawbacks of the prior art.

According to this invention, a foldable rack comprises a lower rack frame that includes front and rear frame-halves, left and right guide rods, two slide pieces, two locking units, and two pairs of link rods. Each of the front and rear frame-halves includes left and right upright rods, and a plurality of vertically spaced-apart horizontal plates each disposed between and connected pivotally to the left and right upright rods. The horizontal plates of the front frame-half are disposed in front of and aligned with the horizontal plates of the rear frame-half, respectively. The left guide rod is disposed between the left upright rods of the front and rear frame-halves. The right guide rod is disposed between the right upright rods of the front and rear frame-halves. Each horizontal plate of the front and rear frame-halves is further connected pivotally to the left and right guide rods. Each of the slide pieces is sleeved slidably on one of the left and right guide rods. The locking units are respectively fixed to the left and right guide rods. Each of the locking units includes a locking element engageable with a respective one of the slide pieces to lock movement of the respective one of the slide pieces. Each of the link rods has top and bottom ends. The top ends of each pair of the link rods are connected pivotally to one of the slide pieces. The bottom ends of one of the pairs of the link rods are connected pivotally and respectively to the left upright rods of the front and rear frame-halves. The bottom ends of the other one of the pairs of the link rods are connected pivotally and respectively to the right upright rods of the front and rear frame-halves. The foldable rack is characterized by an upper rack frame disposed above the lower rack frame and including left and right guide rod extensions that are respectively connected to and that extend upwardly from the left and right guide rods.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of the invention, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a foldable rack disclosed in Taiwanese Publication No. M302941;

FIG. 2 is a perspective view of a foldable rack according to the first preferred embodiment of this invention in an unfolded state;

FIG. 3 is a schematic side view of the first preferred embodiment;

FIG. 4 is a sectional view of the first preferred embodiment taken along line IV-IV of FIG. 3;

FIG. 5 is a view similar to FIG. 4, but illustrating a locking element being disengaged from a protrusion of a slide piece;

FIG. 6 is a schematic view of the first preferred embodiment in a folded state;

FIG. 7 is a perspective view of a foldable rack according to the second preferred embodiment of this invention;

FIG. 8 is a perspective view of a foldable rack according to the third preferred embodiment of this invention in an unfolded state;

FIG. 9 is a perspective view of a foldable rack according to the fourth preferred embodiment of this invention in an unfolded state; and

FIG. 10 is a perspective view of a foldable rack according to the fifth preferred embodiment of this invention in an unfolded state.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present invention is described in greater detail, it should be noted that the same reference numerals have been used to denote like elements throughout the specification.

Referring to FIGS. 2 to 6, a foldable rack according to the first preferred embodiment of the present invention is shown to comprise a lower rack frame 100, an upper rack frame 200, a link unit 30, and two locking units 40 (only one is visible in FIG. 2).

The lower rack frame 100 includes front and rear frame-halves 20, 10 each of which includes left and right upright rods 21, 21′, 11′ (only the left upright rod of the rear frame-half 10 is not visible in FIG. 2), and a plurality of horizontal plates 22, 12 disposed equally spaced apart from each other between top and bottom sections 212, 212′, 112′, 211, 211′, 111′ of the left and right upright rods 21, 21′, 11′. In this embodiment, three horizontal plates 22, 12 are exemplified for each of the front and rear frame-halves 20, 10. Each horizontal plate 22, 12 is disposed between and connected pivotally to the left and right upright rods 21, 21′, 11′ of a corresponding one of the front and rear frame-halves 20, 10. The horizontal plates 22 of the front frame-half 20 are disposed in front of and aligned horizontally with the horizontal plates 12 of the rear frame-half 10, respectively.

The link unit 30 includes left and right guide rods 31, 31′, two slide pieces 32, and two pairs of link rods 33. The left guide rod 31 is disposed between the left upright rods 21 of the front and rear frame-halves 20, 10. The right guide rod 31′ is disposed between the right upright rods 21′, 11′ of the front and rear frame-halves 20, 10. Each of the left and right guide rods 31, 31′ has a top section 312′ (the top section of the left guide rod 31 is not visible in FIG. 2), a bottom section 311, 311′, and three pivot pins 316 spaced apart from each other along the length thereof. Each horizontal plate 22, 12 of the front and rear frame-halves 20, 10 is further connected pivotally to the left and right guide rods 31, 31′ using corresponding pivot pins 316.

Each slide piece 32 is sleeved slidably on a respective one of the left and right guide rods 31, 31′ between the top and bottom sections 311, 312′, 311′ thereof, and has a protrusion 321 projecting therefrom.

Each link rod 33 has top and bottom ends. The top ends of each pair of the link rods 33 are connected pivotally to one of the slide pieces 32. The bottom ends of one of the pairs of the link rods 33 are connected pivotally and respectively to the bottom sections 211 of the left upright rods 21 of the front and rear frame-halves 20, 10. The bottom ends of the other one of the pairs of the link rods 33 are connected pivotally and respectively to the bottom sections 211′, 111′ of the right upright rods 21′, 11′ of the front and rear frame-halves 20, 10.

A positioning element 314 (see FIG. 4) is fixed around the top section 312′ of each of the left and right guide rods 31, 31′ through the pivot pin 316 that connects pivotally topmost ones of the horizontal plates 22, 12 of the front and rear frame-halves 20, 10 to the corresponding one of the left and right guide rods 31, 31′. The positioning element 314 has a rectangular head part 314′.

With reference to FIG. 4, each locking unit 40 includes a locking plate 41 and a biasing element 42. The locking plate 41 has a fulcrummed portion 411 connected pivotally to the positioning element 314, a locking element 412 provided on a bottom end thereof to engage releasably the protrusion 321 of a respective slide piece 32, and a trigger portion 413 opposite to the locking element 412 and disposed below the head part 314′. The biasing element 42 is disposed between the trigger portion 413 and the positioning element 314 so as to bias the trigger portion 413 away from the positioning element 314 and to bias the locking element 412 to engage the protrusion 321.

The upper rack frame 200 includes left and right guide rod extensions 51, 51′ that are respectively connected to and that extend upwardly from the left and right guide rods 31, 31′, and four upper rod sections 53 extended respectively from the upright rods 21, 21′, 11′ of the front and rear frame-halves 20, 10. In this embodiment, each of the left and right guide rod extensions 51, 51′ is connected integrally as one piece with the respective one of the left and right guide rods 31, 31′, and each upper rod section 53 is connected integrally as one piece with the respective one of the upright rods 21, 21′, 11′ of the front and rear frame-halves 20, 10. The upper rack frame 200 further includes two vertically spaced-apart horizontal plates 52, and two vertically spaced-apart horizontal plates 62 disposed in front of and aligned horizontally and respectively with the horizontal plates 52. Each horizontal plate 52 is disposed between and connected pivotally to two of the upper rod sections 53 and the left and right guide rod extensions 51, 51′. Each horizontal plate 62 is disposed between and connected pivotally to the other two of the upper rod sections 53 and the left and right guide rod extensions 51, 51′.

With reference to FIGS. 2 and 3, when the foldable rack of the present invention is in an unfolded state, the left and right upright rods 21, 21′, 11′ of the front and rear frame-halves 20, 10 are disposed farthest away from each other. Since the upper rod sections 53 are connected integrally and respectively to the upright rods 21, 21′, 11′, the upper rod sections 53 are also disposed farthest away from each other. Further, the horizontal plates 22 of the front frame-half 20 are aligned horizontally and respectively with the horizontal plates 12 of the rear frame-half 10, and the horizontal plates 62 are aligned horizontally and respectively with the horizontal plates 52. Through such a configuration, a plurality of shelves for holding objects (not shown) are formed. At this time, with reference to FIG. 4, the trigger portion 413 is moved away from the positioning element 314 by the biasing action of the biasing element 42, and the locking element 412 is engaged to the protrusion 321 of the respective slide piece 32 so as to lock movement of the slide piece 32 relative to the respective guide rod 31, 31′. The slide piece 32 abuts against a bottom end of the positioning element 314, and is positioned thereat. Alignment of the horizontal plates 22, 62 with the respective horizontal plates 12, 52 can thus be ensured.

With reference to FIGS. 5 and 6, when the trigger portion 413 is operated such that the trigger portion 413 is moved close to the positioning element 314, the locking element 412 is moved away from the protrusion 321 so as to disengage from the same, thereby permitting sliding movement of the slide piece 32 relative to the guide rod 31′. At this time, the locking plate 41 can be pushed upwardly so as to move therealong the guide rod 31′ relative to the slide piece 32. As the guide rod 31′ moves upwardly relative to the slide piece 32, the upright rods 21′, 11′ and the upper rod sections 53 move downwardly close to each other, and the horizontal plates 22, 12, 62, 52 pivot downwardly relative to the guide rods 31, 51 close to each other, thereby shifting the foldable rack of the present invention from the unfolded state shown in FIG. 2 to a folded state shown in FIG. 6.

It is worth mentioning that, with reference to FIG. 6, when the foldable rack of the present invention is folded, the upper rod sections 53 abut oppositely against the head part 314′ of the positioning element 314, so that the upright rods 21, 21′, 11′ and the upper rod sections 53 are spaced apart from each other at a small distance. Hence, the foldable rack of the present invention, after being folded, is stable, and has a small volume to facilitate storage, packing, and transport thereof.

Therefore, the foldable rack of the present invention not only can provide a plurality of shelves for holding objects, but also can be folded and unfolded as desired. Further, the locking unit 40 can be operated easily so as to fold and unfold the foldable rack of the present invention.

Referring to FIG. 7, a foldable rack according to the second preferred embodiment of the present invention is shown to be similar to the first preferred embodiment. However, in this embodiment, the upper rack frame 200′ includes only two upper rod sections 53 extended integrally and respectively from the left and right upright rods 11′ (the left upright rod is not visible) of the rear frame-half 10, and the horizontal plate 52 disposed between and connected pivotally to the upper rod sections 53 and the left and right guide rod extensions 51, 51′. The foldable rack in this embodiment is configured as a computer table.

Referring to FIG. 8, a foldable rack according to the third preferred embodiment of the present invention is shown to be similar to the first preferred embodiment. However, in this embodiment, the upper rack frame 200″ includes only a transverse holding member 54 extending between and connected integrally to top ends of the left and right guide rod extensions 51, 51′. The upper rack frame 200″ in this embodiment is used for hanging articles. For example, a plurality of S-hooks can be disposed on the transverse holding member 54 for hanging cups.

Referring to FIG. 9, a foldable rack according to the fourth preferred embodiment of the present invention is shown to be similar to the third preferred embodiment. However, in this embodiment, the upper rack frame (200 a) further includes two connectors 550 each connected between one of the left and right guide rod extensions 51, 51′ and a respective one of the left and right guide rods 31, 31′, so that the left and right guide rod extensions 51, 51′ can be connected detachably and respectively to the left and right guide rods 31, 31′.

Referring to FIG. 10, a foldable rack according to the fifth preferred embodiment of the present invention is shown to be similar to the third preferred embodiment. However, in this embodiment, the transverse holding member 54′ of the upper rack frame (200 b) is configured as an elongated flat plate disposed between and connected to the top ends of the left and right guide rod extensions 51, 51′. A plurality of hooks may be connected to the flat plate for hanging articles, such as cups.

While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements. 

1. A foldable rack comprising: a lower rack frame that includes front and rear frame-halves each of which includes left and right upright rods, and a plurality of vertically spaced-apart horizontal plates each disposed between and connected pivotally to said left and right upright rods, said horizontal plates of said front frame-half being disposed in front of and aligned with said horizontal plates of said rear frame-half, respectively, left and right guide rods, said left guide rod being disposed between said left upright rods of said front and rear frame-halves, said right guide rod being disposed between said right upright rods of said front and rear frame-halves, each of said horizontal plates of said front and rear frame-halves being further connected pivotally to said left and right guide rods, two slide pieces each sleeved slidably on one of said left and right guide rods, two locking units respectively fixed to said left and right guide rods, each of said locking units including a locking element engageable with a respective one of said slide pieces to lock movement of the respective one of said slide pieces, and two pairs of link rods each having top and bottom ends, said top ends of each pair of said link rods being connected pivotally to one of said slide pieces, said bottom ends of one of said pairs of said link rods being connected pivotally and respectively to said left upright rods of said front and rear frame-halves, said bottom ends of the other one of said pairs of said link rods being connected pivotally and respectively to said right upright rods of said front and rear frame-halves; and an upper rack frame disposed above said lower rack frame, and including left and right guide rod extensions that are respectively connected to and that extend upwardly from said left and right guide rods.
 2. The foldable rack of claim 1, wherein each of said left and right guide rod extensions is connected integrally as one piece with a respective one of said left and right guide rods.
 3. The foldable rack of claim 2, wherein said upper rack frame includes four upper rod sections extended respectively from said upright rods of said front and rear frame-halves, and at least two horizontal plates that are aligned horizontally, one of said horizontal plates of said upper rack frame being connected pivotally to said left and right guide rod extensions and two of said upper rod sections, the other one of said horizontal plates of said upper rack frame being connected pivotally to said left and right guide rod extensions and the other two of said upper rod sections.
 4. The foldable rack of claim 2, wherein said upper rack frame includes two upper rod sections extended integrally and respectively from said left and right upright rods of said rear frame-half, and a horizontal plate connected pivotally to said upper rod sections and said left and right guide rod extensions.
 5. The foldable rack of claim 1, wherein said upper rack frame includes a transverse holding member extending between and connected to top ends said left and right guide rod extensions.
 6. The foldable rack of claim 1, further comprising two connectors each connected between one of said left and right guide rod extensions and a respective one of said left and right rods so that said left and right guide rod extensions can be connected detachably and respectively to said left and right guide rods.
 7. The foldable rack of claim 1, further comprising a positioning element fixed around each of said left and right guide rods, each of said slide pieces having a protrusion projecting therefrom to engage said locking element, each of said locking units further including a locking plate connected pivotally to said positioning element, and a biasing element, said locking plate having said locking element provided on one end thereof, and a trigger portion opposite to said locking element, said biasing element being disposed between said positioning element and said trigger portion to bias said trigger portion away from said positioning element and to bias said locking element to engage said protrusion. 